Traditional grills comprise a lower cooking unit and an upper cooking unit, the lower cooking unit comprises a lower shell and a lower cooking plate detachably mounted on the lower shell, the upper cooking unit comprises an upper shell and an upper cooking plate detachably mounted on the upper shell. Usually, the traditional grills further equipped with several plates for using. These equipped plates can not be stored within the grill, and that cause the following disadvantage: first, the equipped plates occupy much space; second, the plates are easy to be fouled. Both of these will cause inconvenience to the users.